title: Theoretical studies of electronic structures, magnetic properties and electron conductivities of one-dimensional Ni(n) (n = 3, 5, 7) complexes.
abstract: Electronic structures, magnetic properties and electron conductivities of linearly aligned one-dimensional (1-D) Ni(II)3, Ni(II)5 and Ni(II)7 complexes, i.e. [Ni3(dpa)4NCS2], [Ni5(tpda)4X2] (X = Cl, CN, N3, NCS) and [Ni7(teptra)4Cl2], are systematically investigated by the broken-symmetry B3LYP calculations and simulations based on an elastic scattering Green's function theory. Calculated spin densities appear only at terminal Ni ions, while inner Ni ions are the closed-shell. The calculated effective exchange integrals (J(ab)) values reproduce well the experimental results that indicate anti-ferromagnetic (AF) interactions between two terminal Ni ions. Natural orbitals and their occupation numbers show that a change in the weak AF couplings by axial ligands in penta-nickel complexes originates in σ-type orbitals. Simulated electron conductivities of [Ni3(dpa)4NCS2] and [Ni5(tpda)4NCS2] semi-quantitatively correspond to the experimental results. By the analyses, it is elucidated that electrons are mainly transmitted by σ-type orbitals, but the bonds between Au and axial ligands are also dominant factors for conductivity.
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan. kitagawa@chem.sci.osaka-u.ac.jp.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Kitagawa
authors.forename: Toru
authors.initials: T
authors.lastname: Matsui
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Nakanishi
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Shigeta
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawakami
authors.forename: Mitsutaka
authors.initials: M
authors.lastname: Okumura
authors.forename: Kizashi
authors.initials: K
authors.lastname: Yamaguchi